Well it's been a week since our purchase of our 09' Mariner and the first night I drove it, I hit the gas pretty good to see what kind of power it had got up to about 4K on the tach and it the car would not move but kept revving then slammed into gear. Called the dealership that I bought it from mind you it was a chevrolet dealer, they could not figure it out...said it was fine kept driving it and over the last week I kept trying to get it re create the problem and I got it to do it two more times but seems to do it when I've driven for 30 plus miles then if I get on it. It may or may not slip again. I have read that these are known for tranny problems....anyone else experience something like this and possible know what it is? It's going to a ford dealer on Friday and is still under the factory powertrain warranty but it's getting close to the end and I'm getting nervous that we purchased a lemon. I wont even get into the tire pressure light coming on and off too.

I would suggest you check the fluid level when the transmission is mis-behaving. The CD4E holds some fluid in the valve body chamber when it gets up to normal operating temperature, but you likely have the 6F35, and I don't know if it does that. The deal is that the fluid expands when it heats, and can get too high in the sump, so they have a thermal valve that closes, trapping fluid to a specific level, when it then overflows and drains back. If the fluid were too low, it could be trapping some, and leaving the pan below recommended level.
Other than that, let Ford take a look.
tom

Tom,
Thank you for the information I will be sure to relay that to the service dept. when it goes in on Friday. I did check the fluid when cold and it barely registered on the dip stick after it was up to operating temps it was all over the stick. I had it going half way up the stick after wiping it of 3-4 times it still showed extremely high. I am not sure which transmission I do have in the Mariner. Yet this morning when I go from a stop it was hessitating really bad to even move but then finally kicked in. I just hope the dealership can get it to act up on them because it doesn't do it all the time only once in a while. I did have a puddle of fluid on the garage floor I was not able to tell the color of it because it seeped into the concrete so fast but has an oily feel but still could be any of the fluids. I put some card board down last night under it to try and catch some but it didn't leak anything last night.

Well just took it to Ford and they have to tear it apart to find out exactly what is going on but they already ordered a new transmission that should be in tuesday just in case they said it threw two different codes...soon as i have more info I will post but they are guessing there are issues with the 5th and 6th gear.